How to Grow Microgreens From Seed

Microgreens grow indoors year-round, so there is no season and no waiting for spring. Sow any day of the year on a bright windowsill or under a simple grow light.

Aim for a room temperature of about 65–75°F (18–24°C), which suits nearly every microgreen. Keep the trays out of cold drafts and away from hot radiators. To keep a steady supply on hand, sow a fresh tray every few days and rotate them — as one tray is harvested, the next is coming up right behind it.

The method is nearly the same for every microgreen:

1. Choose your seed. Use seed sold for microgreens or sprouting, such as broccoli, radish, pea, sunflower, or beet.

2. Soak large seed. Small seeds (broccoli, radish, arugula) go in dry. Large seeds (sunflower, pea) do better with an 8–12 hour soak first.

3. Fill a shallow tray. Use a 1–2 inch layer of fine seed-starting mix or pre-moistened coconut coir in a shallow tray or container with a little drainage.

4. Sow dense and even. Scatter the seed across the surface in a single, even, crowded layer with minimal overlap. Do not bury it — just press it gently into contact with the mix.

5. Mist and cover. Mist the surface, then cover with a blackout dome or a second inverted tray to hold in moisture and darkness.

6. Blackout, then light. Keep it covered in the dark for about 2–4 days until the seeds sprout and lift the cover, then uncover and move it into bright light.

Once the seedlings are uncovered, care is simple:

• Light: give 12–16 hours of bright light a day from a sunny window or a grow light for stocky, colorful greens.
• Water: bottom-water by adding water to the tray beneath so the foliage stays dry, and keep the mix evenly moist but never soggy.
• Airflow: keep gentle air moving around the tray to discourage mold — a cracked window or small fan is plenty.
• Cleanliness: start with clean trays and fresh mix, and avoid overwatering, which is the main cause of problems.
• Temperature: hold a steady 65–75°F for even, healthy growth.

Microgreens are ready when the cotyledon (seed) leaves are fully open and the first true leaves are just beginning to show, usually at about 1–3 inches tall and roughly 1–3 weeks after sowing.

To harvest, gather a handful and cut the stems with clean, sharp scissors just above the soil line. Harvest what you need fresh, or cut the whole tray at once.

Let the cut greens dry a little, then store them unwashed in an airtight container in the fridge and rinse just before eating. Most microgreens do not regrow after cutting — pea shoots are the one exception that may give a small second cut — so simply sow a fresh tray for your next harvest.

Microgreens add fresh flavor and color to almost anything. Pile them on salads, sandwiches, wraps, tacos, and grain or Buddha bowls, fold them into omelets, or scatter them over avocado toast, soups, and pizza as a garnish. Milder types like sunflower and pea also blend beautifully into smoothies.

Beyond flavor, microgreens are prized for nutrition: they are remarkably nutrient-dense, often carrying higher concentrations of vitamins and antioxidants than the full-grown plant. Brassica microgreens like broccoli and radish are an easy way to add compounds such as sulforaphane to your diet.

A few issues come up often, and all are easy to fix:

• Mold vs. root hairs: fine white fuzz on the stems near the seed is usually harmless root hairs; slimy, cobweb-like growth spreading across the soil with a sour smell is mold — improve airflow, water less, and sow thinner.
• Damping off: seedlings collapse at the base from overwatering — ease off the water and increase airflow.
• Leggy or pale greens: tall, floppy, washed-out stems mean not enough light — move them closer to a window or grow light.
• Uneven germination: patchy sprouting comes from uneven sowing or dry spots — sow more evenly and keep moisture consistent.
• Stuck seed hulls: hulls clinging to the leaves can be reduced by misting and a gentle rub, or by using a light weight during the blackout stage.